This proposal explores the neural and psychological mechanisms of cognitive control. Control processes are thought to be fundamentally important in enabling the flexibility, complexity, and sophistication of human cognition. Conversely, breakdowns in cognitive control are a major source of impairment in a wide range of neuropsychiatric disorders, such as Alzheimer's and Parkinson's Disease, schizophrenia, and ADHD. A core component of cognitive control is the ability to be proactive - to prepare attention, thoughts, and actions in advance - based on foreknowledge, expectations, or goals regarding upcoming events. A large body of work has elucidated the neural systems involved in proactive or preparatory control, with current consensus pointing to the importance of dorsal front parietal circuits, along with the midbrain dopamine system and medial frontal cortex. Nevertheless, theoretical progress in specifying the precise functional contributions and interactions of these systems has been slow. Our previous work has demonstrated that challenges for theoretical understanding arise because there are multiple possible control mechanisms that can be flexibly deployed according to the specific task demands, and other factors such as stable individual differences, motivational factors, and the integrity of specific neural control systems. The current application tests the hypothesis that important qualitative distinctions exist between preparation based on: a) attentional vs. intentional control;b) intentional vs. volitional control;and c) representations at different levels of a goal hierarchy. These hypotheses will be tested in an integrated series of behavioral and neuroimaging studies (using state-of-the-art functional magnetic resonance imaging methods and analytical techniques) that systematically examine these distinctions from within a common set of experimental paradigms, in both young and older adults, and in relation to individual difference variables. Success in this work would represent a significant theoretical advance, by clarifying the neural mechanisms and behavioral consequences of how control over cognition is achieved. This project has high relevance for public health in terms of the potential to provide critical information regarding the neural and psychological bases of both the transient lapses and sustained impairments in cognitive control suffered by both healthy individuals and clinical populations. Such knowledge could be used to drive the development of more effective interventions. PUBLIC HEALTH RELEVANCE: This project has high relevance for public health by providing critical information about the role of avoidance motivation (i.e., the drive to avoid negative outcomes) in vulnerability to substance abuse. Specifically, avoidance motivation may have a significant impact on brain function and high-level cognition (e.g., planning and decision- making strategies), with individuals at risk for substance abuse showing an impaired response in such situations. An improved understanding of the brain basis of this process is necessary for determining why and how impaired decision-related behaviors might lead to problems with substance abuse for some individuals, and as such developing appropriate corrective interventions to address, and hopefully prevent, such problems.